import RPi.GPIO as gpio

from dataclasses import dataclass


@dataclass
class Encoder:
    pin_a: int
    pin_b: int

    _curr_steps: int = 0

    def setup(self):
        gpio.setmode(gpio.BCM)

        gpio.setup(self.pin_a, gpio.IN)
        gpio.setup(self.pin_b, gpio.IN)
        gpio.add_event_detect(self.pin_a,
                              gpio.RISING,
                              callback=self._event_detect)
        gpio.add_event_detect(self.pin_b,
                              gpio.RISING,
                              callback=self._event_detect)

    def _event_detect(self, pin):
        a = gpio.input(self.pin_a)
        b = gpio.input(self.pin_b)

        if a ^ b:
            self._curr_steps += 1 if a else -1

    @property
    def angle(self) -> float:
        return self._curr_steps / 5000 * 360